Sailing Boat Winch Rotor with Tilted Relief Elements

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Solution Overview

Problem

Existing winches for sailing boats face issues with vertical movement of rope windings during sail position adjustments, causing damage to the rope due to excessive friction, particularly in cruising boats where frequent rope replacement leads to economic costs.

Innovation Solution

A winch design featuring a rotor body with tilted recess and relief elements on its outer surface, which reduces vertical rope movement and concentrates friction at specific points, minimizing rope damage while maintaining effective control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the outer surface of the rotor body is treated to increase friction (e.g., sandblasting, knurling), then the friction between the rope and rotor body is improved, but the rope is damaged in relatively short time periods

Engineering Contradiction:
Improvefriction between rope and rotor bodyVSAvoidrope lifespan
Core Design Contradiction:
ForceVSDuration of action of moving object

Solution Approach 1:

The invention applies local quality by providing relief elements only in specific zones of the rotor body rather than treating the entire surface. The relief elements are concentrated in areas where rope contact occurs during winding operations, creating localized friction enhancement zones that protect the rope from damage while maintaining necessary grip. This selective application prevents the uniform damage caused by comprehensive surface treatments like sandblasting or knurling.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The relief elements act as intermediaries between the rope and the rotor body surface. Instead of direct contact between the rope and the rough treated surface, the relief elements mediate the interaction, concentrating friction forces at specific contact points. This intermediary structure reduces the cumulative damage to the rope while maintaining effective friction for rope control during sailing operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the rope windings move vertically towards the upper part of the rotor body during loosening operations, then the rope control by the user is worsened, but using a frustoconical rotor body shape reduces this movement

Engineering Contradiction:
Improverope control by userVSAvoidvertical movement of rope windings
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The invention employs asymmetry by tilting the relief elements at a specific angle (5-15 degrees) relative to the horizontal plane. This asymmetric orientation creates a geometric constraint that counteracts the vertical movement tendency of the rope windings. The tilted relief elements guide the rope along a more controlled path, preventing excessive vertical displacement during loosening operations while maintaining user control.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The relief elements are designed with curved surfaces that follow the natural wrapping path of the rope around the rotor body. This curvature works in conjunction with the tilt angle to smoothly guide the rope windings, reducing abrupt vertical movements and improving the overall ease of operation during rope handling.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Duration of action of moving object

If relief elements are applied onto the rotor body surface in vertical position, then friction is concentrated at specific points reducing rope damage, but the vertical movement of rope windings towards the upper part is not sufficiently reduced

Engineering Contradiction:
Improverope lifespanVSAvoidvertical movement of rope windings
Core Design Contradiction:
Duration of action of moving objectVSShape

Solution Approach 1:

The key innovation is tilting the relief elements away from the vertical position. By angling the relief elements at 5-15 degrees relative to the horizontal plane, the invention simultaneously achieves both objectives: concentrating friction at specific points to protect the rope while the tilted geometry actively counteracts vertical movement of the windings during operation.

Inventive Principle:
Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The tilted recess and relief elements on the winch reduce rope vertical movement and enhance friction distribution, extending rope lifespan and reducing maintenance costs by minimizing wear and tear.

Implementation Method 1

The presence of said relief elements allows to concentrate the friction between the windings of the rope and the rotor body of the winch in those specific points of the rope which are in contact with the same relief elements only, thus reducing the damage of the rope

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

said recess elements and said relief elements extend along a second direction only, said second direction being tilted at a predefined angle with respect to said first direction, wherein said predefined angle is greater than 0° and lower than about 60°

Methodology Applied
Scientific EffectMechanical constraint through geometric shape: Geometry

Data Source

PatentEP1852386B1Winch for sailing boats
Publication Date: 2008.04.02 HARKEN ITAL
  • EP1852386B1 patent drawingFigure 1
  • EP1852386B1 patent drawingFigure 2

AI summary

The invention refers to a winch (1) for sailing boats comprising a stator body adapted to be integrally mounted on a deck (2) of a sailing boat and a rotor body (3) coaxially and rotatably fitted on the stator body along a primary shaft extended along a first direction (x). The rotor body (3) comprises a body portion (5) adapted to receive the windings of a control rope (4) of a sail of the sailing boat. Such rotor body portion (5) comprises an outer lateral surface (7) wherein a plurality of recess elements (8) and a plurality of elements in relief (9) with respect to said recess elements (8) are defined. In accordance with the invention, the recess elements (8) and the relief elements (9) extend along a second direction (y) tilted at a predefined angle (α) with respect to said first direction (x).